Who is Dimitri Belikov from Frostbite and what is their importance?

Dimitri Belikov is a twenty-four-year-old dhampir who works as an instructor at St. Vladimir's Academy. Dimitri is Rose's combat trainer and his job to teach Rose how to defend herself physically. During Rose's fight against Victor Dashkov, Dimitri and Rose were placed under a lust spell that caused them to become intimate. However, Dimitri broke the spell before it got too intimate and told Rose that the two of them could not pursue a relationship because of the dangers it would pose in their future as guardians to Lissa.